Powertop is Linux tool to find out what is using power on a laptop. This program only works on Intel based laptops. It is very good software to extend Laptop battery life time. I’ve tested this software with following Intel based laptops: => My Sony VAIO Laptop => My Dell 6400 Laptop => My office HP / Compaq Laptop

From the project page:

Computer programs can make your computer use more power. PowerTOP is a Linux tool that helps you find those programs that are misbehaving while your computer is idle.

PowerTOP combines various sources of information from the kernel into one convenient screen so that you can see how well your system is doing at saving power, and which components are the biggest problems.

PowerTOP has these four basic goals:

=> Show how well your system is using the various hardware power-saving features => Show you the culprit software components that are preventing optimal usage of your hardware power savings => Help Linux developers test their application and achieve optimal behavior => Provide you with tuning suggestions to achieve low power consumption